1. Field of the Invention
The present invention relates to portable well servicing equipment having a foldable service conduit thereon for conducting pressurized fluids to a wellhead, and more particularly relates to means and a method for insuring the proper sequence of folding and unfolding the several sections of the service conduit.
2. Description of the Prior Art
In order to improve the output of oil from oil wells, it is frequently desirable to inject fluid at high pressure, such as 20,000 psi, to fracture the producing rock formation or to dissolve or displace the flow obstructing materials. Pipe carrying vehicles are known for carrying pipes to and from the wellhead area, which pipes must be manually assembled on the ground and thereafter must be manually disassembled and loaded on the vehicle.
Assignee's above referred to application discloses a service line or foldable conduit connected together by swivel joints and supported on a vehicle by a telescopic boom, which conduit must be extended and retracted in order to unfold the conduit into operative extended position and fold the conduit in retracted transport position on the vehicle. However, no provision is made in this prior art apparatus to prevent rapid free-fall of certain sections of the conduit during extension and retraction of the conduit which is dangerous to personnel near the vehicle and which, upon occasion, may adversely affect the desired sequence of unfolding the several sections.